In the operation of a construction machine, it is quite common for the machine to experience several different work modes. In a wheel loader for example, various tasks include truck loading, load and carry and other more specialized tasks. In truck load and carry operations for example, there is an abundance of machine movement in which the machine will attain relatively high speeds as it carries a load from one place to another. The braking application in both the front and rear axles is severe since they are required to bring the machine to a stop after attaining these high speeds. This frequently causes the brakes, and the oil within the axle housings in which the brakes are located, heat up to excessive temperatures. In other instances such as truck loading or instances where there is a high degree of implement use without much machine travel, the brakes are not utilized much and the axle temperature is not a concern. However, in these situations, enhancement of the engine's cooling system would be very beneficial to ensure that the temperature of the engine does not become excessive.
In both instances set forth above, heat is a by-product of the different operations that is known to cause excessive wear and potentially premature failure of various components. Where excessive engine heat is concerned several common remedies have been known to work quite well. They include enlarged cooling system capacities or additional cooling mediums within the typical cooling system. With respect to the heat build up experienced in axle assemblies, several methods have also been employed to reduce heat. Typically, some type of system is employed to circulate the oil within the axle housings through a air-to-oil cooler, or to circulate a cooler fluid through the oil within the axle housing. These systems have been known to work with limited success and, in most instances, are relatively complex in nature and require many extra components to attain the desired results. In addition, these systems are operational all the time and are extremely limited in their versatility.
The present invention is directed to overcoming one or more of the problems listed above.